This is huge. Not only are micro reactors far more economical, it dramatically reduces the need to maintain a massive nationwide grid and provides flexibility to people in remote areas including greater autonomy. Efficiency should be greater without massive transmission line losses. Might start fewer fires in California too.
Experience to date has been the opposite. They have diseconomies of scale in construction and operation. The proponents claim they will make up for this somehow, for example by making the reactors in factories, but note that NuScale has given up on that and is going to have the parts fabricated by others and assembled on site, just like larger reactors.